Terry was killed in a gun battle occurred in 2010 on the Arizona-Mexico border

A Mexican man was sentenced Monday to 30 years' imprisonment in a border agent's 2010 shooting death linked to the federal government's "Fast and Furious" gun-tracking operation, according to a spokesperson for the U.S. District Court in Tucson.

Manuel Osorio-Arellanes, 37, had pleaded guilty to first-degree murder in October 2012 in the slaying of U.S. Border Patrol agent Brian Terry. The judge also sentenced Osorio-Arellanes to five years of supervised release.

"We are not celebrating," Terry's family said in a statement. "Today we recognized justice has been served and we believe the 30 year sentence imposed on this particular defendant is an appropriate sentence... We remain hopeful that all suspects in this murder will be brought to justice."

In his plea agreement, Osorio-Arellanes agreed the shot that killed Terry was fired by a member of his group, although he did not claim to have personally fired the shot or blame someone else specifically for the crime.

The Terry case has been controversial because two rifles from the "Fast and Furious" operation were found at the scene of his death. But U.S. officials have not produced evidence proving that Terry was killed with either of those guns.

Osorio-Arellanes was wounded and arrested at the scene. As part of the deal, prosecutors agreed not to seek the death penalty and dropped other charges against him.

Other suspects have been apprehended, the U.S. attorney's office reported.

Lionel Portillo-Meza and Ivan Soto-Barraza have been captured in Mexico. These defendants are charged with first-degree murder, second-degree murder, conspiracy to interfere with commerce by robbery, attempted interference with commerce by robbery, use and carrying a firearm during a crime of violence, assault on a federal officer and possession of a firearm by a prohibited person.

The indictment also alleges the defendants assaulted Border Patrol agents William Castano, Gabriel Fragoza and Timothy Keller, who were with Terry during the firefight.

In a related case, Rito Osorio-Arellanes, pleaded guilty to conspiracy to interfere with commerce by robbery and was sentenced to eight years in prison in January 2013. Rito Osorio-Arellanes was not present at the incident that resulted in Terry's murder.